Legal claims defining the scope of protection. Each claim is shown in both the original legal language and a plain English translation.
1. A method comprising: dividing a block of complex-valued symbols into a plurality of sets of complex-valued symbols; transform precoding each of the plurality of sets of complex-valued symbols into a block of transform-precoded complex-valued symbols; and generating an Orthogonal Frequency Division Multiplex (OFDM) signal comprising a plurality of OFDM subcarriers modulated by the transform-precoded complex-valued symbols, wherein the transform precoding generates a plurality of orthogonal spreading codes to provide a superposition of the plurality of OFDM subcarriers with a reduced peak-to-average-power ratio.
This invention relates to wireless communication systems, specifically techniques for reducing the peak-to-average power ratio (PAPR) in Orthogonal Frequency Division Multiplexing (OFDM) signals. OFDM is widely used in wireless communications, but it suffers from high PAPR, which can lead to inefficiencies in power amplifiers and increased signal distortion. The invention addresses this by applying transform precoding to complex-valued symbols before OFDM modulation. The method involves dividing a block of complex-valued symbols into multiple sets. Each set is then processed through a transform precoding step, which generates a block of transform-precoded complex-valued symbols. These precoded symbols are used to modulate multiple OFDM subcarriers. The transform precoding step generates orthogonal spreading codes, which create a superposition of the OFDM subcarriers. This superposition reduces the PAPR of the resulting OFDM signal, improving power amplifier efficiency and reducing distortion. The technique leverages orthogonal spreading to distribute the energy of the symbols across subcarriers, minimizing peaks in the time-domain signal. By applying this method, the system achieves a more uniform power distribution, making it suitable for high-efficiency wireless communication systems. The approach is particularly useful in scenarios where power efficiency and signal integrity are critical, such as in 5G and beyond-5G networks.
2. The method of claim 1 , wherein the transform precoding spreads the block of complex-valued symbols with a plurality of orthogonal spreading codes comprising complex-valued coefficients of a discrete Fourier transform (DFT) to produce the block of transform-precoded complex-valued symbols.
This invention relates to wireless communication systems, specifically to techniques for precoding data symbols to improve transmission efficiency and reliability. The problem addressed is the need for efficient spreading of complex-valued symbols in wireless transmissions to enhance performance in multi-user or multi-antenna environments. The method involves transforming a block of complex-valued symbols using a set of orthogonal spreading codes. These spreading codes are derived from the complex-valued coefficients of a discrete Fourier transform (DFT). The DFT-based spreading ensures that the precoded symbols maintain orthogonality, reducing interference between different data streams or users. This approach is particularly useful in systems where multiple antennas or users share the same frequency resources, as it helps mitigate inter-stream interference and improves signal quality. The precoding process involves applying the DFT-based spreading codes to the block of symbols, resulting in a block of transform-precoded complex-valued symbols. These precoded symbols are then transmitted over the wireless channel. The use of DFT coefficients ensures that the spreading codes are orthogonal, which is critical for maintaining signal integrity in multi-user or multi-antenna scenarios. This technique can be applied in various wireless communication standards, including those using orthogonal frequency-division multiplexing (OFDM) or other multi-carrier modulation schemes. The method enhances spectral efficiency and reliability by optimizing the distribution of symbols across the available resources.
3. The method of claim 2 , wherein the DFT is a fast Fourier transform (FFT).
A system and method for signal processing involves performing a discrete Fourier transform (DFT) on an input signal to convert it from the time domain to the frequency domain. The DFT is specifically implemented as a fast Fourier transform (FFT), which is a computationally efficient algorithm for calculating the DFT. The input signal may be a time-domain signal, such as an audio or sensor signal, that requires frequency analysis. The FFT algorithm reduces the number of computations needed compared to a direct DFT, making it suitable for real-time or high-speed applications. The output of the FFT provides frequency-domain representations of the input signal, which can be used for further analysis, filtering, or feature extraction. This approach is particularly useful in applications where rapid frequency analysis is required, such as in digital communications, audio processing, or signal monitoring systems. The FFT implementation may include optimizations for specific hardware or software environments to enhance performance and accuracy. The method ensures that the frequency-domain data is accurately derived from the input signal while minimizing computational overhead.
6. The method of claim 1 , comprising: mapping the block of transform-precoded complex-valued symbols to physical resource blocks assigned for transmission of a physical uplink shared channel.
This invention relates to wireless communication systems, specifically methods for transmitting data on a physical uplink shared channel (PUSCH) in a cellular network. The problem addressed is efficiently mapping transform-precoded complex-valued symbols to physical resource blocks (PRBs) for uplink transmission, ensuring proper allocation and utilization of available radio resources. The method involves receiving a block of transform-precoded complex-valued symbols, which are generated by applying a transform precoding technique (such as discrete Fourier transform spreading) to input data. These symbols are then mapped to specific physical resource blocks assigned for PUSCH transmission. The mapping ensures that the precoded symbols are correctly placed within the allocated PRBs, maintaining orthogonality and minimizing interference. The process may include determining the number of available PRBs, adjusting the symbol mapping based on resource block assignments, and ensuring proper alignment with the uplink transmission framework. This technique is particularly useful in scenarios where transform precoding is used to improve uplink transmission efficiency, such as in single-carrier frequency-division multiple access (SC-FDMA) systems. By optimizing the mapping of precoded symbols to PRBs, the method enhances spectral efficiency and reliability in uplink communications. The approach is compatible with existing wireless standards and can be implemented in user equipment (UE) or base stations to improve uplink data transmission performance.
7. The method of claim 6 , wherein the mapping is responsive to an assignment of spectrum resources for selecting a plurality of OFDM subcarriers corresponding to at least one OFDM symbol interval.
This invention relates to wireless communication systems, specifically to methods for mapping data to orthogonal frequency-division multiplexing (OFDM) subcarriers in response to spectrum resource assignments. The problem addressed is the efficient allocation and utilization of available spectrum resources in OFDM-based communication systems, where data must be mapped to specific subcarriers and symbol intervals to optimize transmission performance. The method involves dynamically assigning spectrum resources by selecting a plurality of OFDM subcarriers corresponding to at least one OFDM symbol interval. This selection is based on the assignment of spectrum resources, which may include frequency bands, time slots, or other resource blocks allocated for communication. The mapping process ensures that data is distributed across the chosen subcarriers in a manner that maximizes spectral efficiency, minimizes interference, and adapts to varying channel conditions. The method may also involve determining the number of subcarriers and symbol intervals to be used, as well as their specific positions within the available spectrum. This allows for flexible and adaptive resource allocation, enabling the system to support different modulation schemes, data rates, and quality-of-service requirements. The approach is particularly useful in systems where spectrum resources are dynamically allocated, such as in cognitive radio networks or 5G/6G wireless systems. By dynamically mapping data to subcarriers in response to spectrum assignments, the method improves the efficiency and reliability of wireless communications, reducing the likelihood of collisions and enhancing overall system throughput.
8. The method of claim 6 , wherein at least one of the transform precoding and the mapping is configured to weight each of the plurality of OFDM subcarriers with an amplitude scaling factor to adjust gain of the superposition.
This invention relates to wireless communication systems, specifically techniques for improving signal transmission in orthogonal frequency-division multiplexing (OFDM) systems. The problem addressed is optimizing signal superposition in multi-user or multi-antenna scenarios to enhance transmission efficiency and reliability. The invention focuses on adjusting the gain of superimposed signals by applying amplitude scaling factors to individual OFDM subcarriers during precoding or mapping stages. The method involves transmitting data using multiple OFDM subcarriers, where each subcarrier carries a portion of the signal. To improve superposition performance, the system applies amplitude scaling to each subcarrier. This scaling adjusts the gain of the superimposed signal, ensuring proper power distribution across subcarriers. The scaling can be applied during transform precoding, which converts data symbols into a format suitable for transmission, or during the mapping stage, where symbols are assigned to specific subcarriers. The scaling factors are selected to optimize signal quality, reduce interference, or balance power allocation. This technique is particularly useful in scenarios where multiple signals are transmitted simultaneously, such as in multi-user MIMO (MU-MIMO) systems or non-orthogonal multiple access (NOMA) schemes. By dynamically adjusting subcarrier gains, the system can improve spectral efficiency and mitigate interference, leading to better overall performance. The invention ensures that the superposition of signals remains stable and efficient, even under varying channel conditions.
9. The method of claim 6 , wherein the mapping is configured to select the plurality of OFDM subcarriers according to at least one of a frequency division multiple access scheme, a time division multiple access scheme, a space division multiple access scheme, a code division multiple access scheme, and a frequency-hoping scheme.
This invention relates to wireless communication systems, specifically methods for selecting orthogonal frequency-division multiplexing (OFDM) subcarriers in multi-user environments. The problem addressed is efficient resource allocation to maximize spectral efficiency while minimizing interference among users. The method involves mapping multiple OFDM subcarriers to different users based on one or more access schemes. These schemes include frequency division multiple access (FDMA), where subcarriers are assigned to users in distinct frequency bands; time division multiple access (TDMA), where subcarriers are allocated in time slots; space division multiple access (SDMA), where spatial separation is used to assign subcarriers; code division multiple access (CDMA), where unique spreading codes differentiate users; and frequency-hopping schemes, where subcarriers are dynamically reassigned across frequencies. The mapping dynamically adjusts subcarrier selection to optimize throughput, reduce collisions, and improve signal integrity. This approach enhances system capacity by leveraging multiple access techniques to manage interference and improve data transmission reliability in dense user environments. The method is particularly useful in 5G and beyond networks where efficient spectrum utilization is critical.
10. The method of claim 1 , comprising: scrambling a block of bits of one subframe of a physical uplink shared channel resulting in a block of scrambled bits; and modulating the block of scrambled bits resulting in the block of complex-valued symbols.
This invention relates to wireless communication systems, specifically to methods for processing data in the physical uplink shared channel (PUSCH) of a subframe. The problem addressed is efficient and secure transmission of uplink data in wireless networks, particularly in scenarios requiring scrambling and modulation to ensure data integrity and reduce interference. The method involves scrambling a block of bits from a subframe of the PUSCH to produce a scrambled bit block. Scrambling is a technique used to randomize the data sequence, improving security and reducing interference with other transmissions. The scrambled bits are then modulated to generate a block of complex-valued symbols, which are suitable for transmission over the wireless channel. Modulation converts the digital data into analog signals that can be transmitted via radio waves. The scrambling process ensures that the transmitted data is randomized, making it harder to intercept or interfere with. The modulation step converts the scrambled bits into symbols that can be efficiently transmitted and later demodulated by the receiver. This method is particularly useful in wireless communication systems where multiple users share the same frequency resources, as it helps mitigate interference and improve overall system performance. The invention is applicable in various wireless communication standards, including but not limited to LTE (Long-Term Evolution) and 5G NR (New Radio), where efficient uplink data transmission is critical. By scrambling and modulating the data, the method ensures reliable and secure communication between the user equipment (UE) and the base station.
11. The method of claim 10 , wherein the scrambling is configured to scramble the block of bits into a block of scrambled bits with at least one pseudo-noise code.
This invention relates to data scrambling techniques used in communication systems, particularly for securing or randomizing data blocks to prevent interference or improve transmission efficiency. The method involves scrambling a block of bits into a block of scrambled bits using at least one pseudo-noise (PN) code. The scrambling process ensures that the original data is transformed in a way that is difficult to reconstruct without knowledge of the PN code, enhancing security or reducing correlation effects in signal transmission. The PN code used in scrambling is a deterministic sequence that appears random, providing a reliable yet reversible transformation. This technique is particularly useful in wireless communications, digital broadcasting, or any system where data integrity and interference mitigation are critical. The method may be applied in conjunction with other encoding or modulation schemes to further enhance performance. The use of a PN code allows for controlled scrambling, ensuring that the scrambled data can be properly descrambled at the receiver end while maintaining the desired properties of the original data. This approach helps in reducing peak-to-average power ratio (PAPR) in transmitted signals and improving resistance to interference.
12. The method of claim 1 , wherein the transform precoding is applied according to z ( l · M sc PUSCH + k ) = 1 M sc PUSCH ∑ i = 0 M sc PUSCH - 1 d ( l · M sc PUSCH + i ) e - j 2 π ik M sc PUSCH , wherein: the block of complex-valued symbols and the block of transform-precoded complex-valued symbol comprises a plurality of resource elements; l represents a time-domain index of each of the plurality of resource elements; k represents a frequency-domain index of each of the plurality of resource elements; M sc PUSCH is a scheduled bandwidth for uplink transmission expressed as a number of subcarriers; d(l·M sc PUSCH +i) represents resource elements of the block of complex-valued symbols; and z(l·M sc PUSCH +k) represents resource elements of the block of transform precoded complex-valued symbols.
This invention relates to wireless communication systems, specifically to a method for applying transform precoding in uplink transmissions. The problem addressed is the efficient and accurate transformation of complex-valued symbols in uplink communications, particularly in scenarios involving scheduled bandwidths and resource allocation. The method involves transforming a block of complex-valued symbols into a block of transform-precoded complex-valued symbols. The transformation is performed using a discrete Fourier transform (DFT) operation, where each resource element in the output block is computed as a weighted sum of the input resource elements. The weights are determined by a phase factor that depends on the frequency-domain index and the scheduled bandwidth. The scheduled bandwidth for uplink transmission, denoted as M sc PUSCH, is expressed as a number of subcarriers. The time-domain index (l) and frequency-domain index (k) are used to map the resource elements in the input and output blocks. The input resource elements are represented by d(l·M sc PUSCH +i), where i is an index within the block. The output resource elements are represented by z(l·M sc PUSCH +k), which are the transform-precoded symbols. This method ensures that the transform precoding is applied in a structured manner, optimizing the use of available subcarriers and improving the efficiency of uplink transmissions. The approach is particularly useful in systems where precise resource allocation and signal processing are critical for maintaining communication quality.
13. The method of claim 12 , wherein: the transform precoding spreads the block of complex-valued symbols with a plurality of orthogonal spreading codes comprising complex-valued coefficients of a discrete Fourier transform (DFT) to produce the block of transform precoded complex-valued symbols; and M sc PUSCH is a length of the DFT corresponding to the plurality of orthogonal spreading codes.
This invention relates to wireless communication systems, specifically to techniques for improving uplink data transmission efficiency in scenarios where multiple users share the same time-frequency resources. The problem addressed is the need for efficient precoding methods that reduce interference and enhance spectral efficiency in multi-user environments. The method involves transforming a block of complex-valued symbols using a transform precoding technique. The precoding process spreads the symbols with a set of orthogonal spreading codes, where each code consists of complex-valued coefficients derived from a discrete Fourier transform (DFT). The length of the DFT, denoted as M sc PUSCH, determines the number of orthogonal spreading codes available. By applying these DFT-based spreading codes, the method generates a block of transform precoded complex-valued symbols that are better suited for transmission over shared uplink channels, such as in Physical Uplink Shared Channel (PUSCH) scenarios. This approach helps mitigate interference and improves data transmission reliability in multi-user uplink communications. The use of DFT-based spreading ensures orthogonality among different users' signals, enhancing overall system performance.
14. The method of claim 13 , wherein: each transform-precoded set of complex-valued symbols of the block of transform-precoded complex-valued symbols is a single-carrier frequency division multiple access symbol; and said each transform precoded set of complex-valued symbols is processed by the DFT.
This invention relates to wireless communication systems, specifically improving data transmission efficiency in single-carrier frequency division multiple access (SC-FDMA) systems. The problem addressed is optimizing the processing of transform-precoded complex-valued symbols to enhance spectral efficiency and reduce interference in multi-user environments. The method involves generating a block of transform-precoded complex-valued symbols, where each set of symbols within the block is an SC-FDMA symbol. Each set undergoes discrete Fourier transform (DFT) processing to convert time-domain symbols into the frequency domain. This transformation enables efficient subcarrier mapping and reduces peak-to-average power ratio (PAPR), which is critical for power-limited devices like mobile terminals. The DFT processing ensures orthogonality between user signals, minimizing inter-user interference in the uplink of cellular networks. The technique is particularly useful in 4G LTE and 5G NR systems, where SC-FDMA is employed for uplink transmissions. By applying DFT to each symbol set, the method maintains low PAPR while supporting high data rates and reliable communication. The approach is compatible with existing SC-FDMA frameworks, offering backward compatibility with legacy systems. The invention improves spectral efficiency and reliability in wireless networks by optimizing symbol processing at the transmitter side.
15. The method of claim 12 , wherein: the block of transform-precoded complex-valued symbols comprises carrier interferometry symbol values (w n ); and the block of complex-valued symbols comprises data symbols (s n ).
This invention relates to a method for processing complex-valued symbols in communication systems, particularly focusing on carrier interferometry (CI) modulation techniques. The method addresses the challenge of efficiently encoding and transmitting data symbols while maintaining spectral efficiency and reducing interference. The method involves generating a block of transform-precoded complex-valued symbols, where the block includes carrier interferometry symbol values (w_n). These values are derived from data symbols (s_n) through a transformation process that optimizes signal transmission. The data symbols (s_n) represent the original information to be transmitted, while the carrier interferometry symbol values (w_n) are processed versions of these data symbols, designed to enhance spectral properties and reduce interference in the communication channel. The transformation process may involve applying a precoding technique that modifies the data symbols to produce the carrier interferometry symbol values. This precoding step ensures that the transmitted signal adheres to specific spectral and interference constraints, improving overall system performance. The method is particularly useful in wireless communication systems where spectral efficiency and interference mitigation are critical. By utilizing carrier interferometry symbol values (w_n) derived from data symbols (s_n), the method enables efficient transmission of information while maintaining signal integrity and minimizing interference with other signals in the same frequency band. This approach is beneficial for applications requiring high data rates and reliable communication in challenging environments.
16. The method of claim 15 , wherein carrier interferometry code chip values are arranged with respect to a plurality of phase spaces.
This invention relates to carrier interferometry (CI) systems, specifically improving signal processing by arranging CI code chip values across multiple phase spaces. The technology addresses challenges in signal detection and interference mitigation in communication systems, particularly in environments with multipath interference or low signal-to-noise ratios. By distributing CI code chip values across different phase spaces, the system enhances signal robustness and reduces interference effects. The method involves generating CI code chips, which are then mapped to distinct phase spaces to optimize signal transmission and reception. This arrangement allows for better discrimination between desired signals and unwanted interference, improving overall system performance. The technique is particularly useful in wireless communication systems, radar applications, and other scenarios where signal integrity is critical. The arrangement of CI code chip values in phase spaces enables more efficient signal processing, leading to improved accuracy and reliability in signal detection and decoding. The invention builds on prior methods of CI coding by introducing a structured phase-space distribution to enhance signal quality and system efficiency.
17. The method of claim 16 , wherein the plurality of phase spaces comprises orthogonal phase spaces.
A system and method for processing signals involves analyzing multiple phase spaces to extract information. The method includes generating a plurality of phase spaces from a signal, where each phase space represents a different transformation or projection of the signal data. These phase spaces are used to identify patterns, features, or relationships within the signal that may not be apparent in a single representation. The method further includes processing the phase spaces to derive meaningful insights, such as detecting anomalies, classifying signals, or reconstructing the original signal with improved accuracy. In one implementation, the phase spaces are orthogonal, meaning they are mathematically independent and do not overlap in their representation of the signal. This orthogonality ensures that the information captured in each phase space is distinct, reducing redundancy and enhancing the efficiency of the analysis. By leveraging orthogonal phase spaces, the method can more effectively separate and analyze different components of the signal, improving the robustness and reliability of the results. The technique is applicable in various domains, including communications, signal processing, and data analysis, where extracting meaningful information from complex signals is critical.
18. The method of claim 16 , wherein each of the data symbol values is impressed upon one of the plurality of phase spaces.
A method for encoding data symbols in a communication system involves modulating data symbols by impressing each symbol value onto a distinct phase space within a multi-dimensional signal space. The technique leverages multiple phase spaces to enhance data transmission efficiency and reliability. Each phase space represents a unique set of phase angles or phase-related parameters that can be independently modulated to carry distinct data values. By distributing data symbols across these phase spaces, the method improves spectral efficiency and reduces interference susceptibility. The approach is particularly useful in high-density modulation schemes where traditional single-phase modulation may limit performance. The method may be applied in wireless communication systems, optical networks, or other data transmission technologies requiring robust and efficient encoding. The use of multiple phase spaces allows for higher data rates while maintaining signal integrity, addressing challenges in high-speed data transmission where conventional modulation techniques may suffer from distortion or noise. The technique can be combined with other modulation methods to further optimize performance in diverse communication environments.
19. The method of claim 15 , wherein the number of carrier interferometry symbol values is different than the number of data symbols.
A system and method for wireless communication involves transmitting and receiving data using carrier interferometry (CI) modulation. The technology addresses challenges in wireless communication, such as improving spectral efficiency and reducing interference in multi-user environments. The method encodes data symbols into CI symbol values, where each CI symbol value represents a unique phase shift applied to a carrier signal. The encoded symbols are then transmitted over a communication channel. At the receiver, the CI symbol values are decoded back into the original data symbols. The method allows multiple users to share the same frequency band by assigning unique phase shifts to each user, minimizing interference. The invention also includes techniques for synchronizing transmitters and receivers to ensure accurate phase alignment. In some implementations, the number of CI symbol values differs from the number of data symbols, allowing for flexible mapping between data and CI symbols to optimize transmission efficiency. The system may be used in various wireless applications, including cellular networks, IoT devices, and satellite communications.
20. The method of claim 1 , wherein each of the plurality of sets of complex-valued symbols is a single carrier frequency division multiple access (SC-FDMA) symbol.
This invention relates to wireless communication systems, specifically to methods for transmitting data using Single Carrier Frequency Division Multiple Access (SC-FDMA). SC-FDMA is a modulation technique used in uplink transmissions to reduce peak-to-average power ratio (PAPR) while maintaining spectral efficiency. The problem addressed is optimizing the transmission of complex-valued symbols in SC-FDMA systems to improve performance and reliability. The method involves organizing data into multiple sets of complex-valued symbols, where each set corresponds to an SC-FDMA symbol. These symbols are processed to ensure efficient transmission over a wireless channel. The technique leverages the properties of SC-FDMA, such as low PAPR and resistance to inter-symbol interference, to enhance communication quality. By structuring the data into SC-FDMA symbols, the method ensures compatibility with existing wireless standards while improving transmission efficiency. The approach may include steps such as symbol mapping, modulation, and resource allocation to optimize the use of available bandwidth. The method is particularly useful in scenarios where multiple users share the same frequency resources, as SC-FDMA allows for efficient multiplexing. The invention aims to provide a robust and spectrally efficient transmission scheme for wireless communication systems.
21. The method of claim 1 , comprising generating a time-continuous signal defined by: s l ( t ) = ∑ k = - [ N RB UL N sc RB / 2 ] [ N RB UL N sc RB / 2 ] - 1 a k ( - ) , l e j 2 π ( k + 1 / 2 ) Δ f ( t - N CP , l T s ) , wherein: N sc RB is a resource block size in a frequency domain express as a number of subcarriers; N RB UL is an uplink bandwidth configuration express in multiples of N sc RB ; a k (−) ,l is a value of a resource element; Δf is subcarrier spacing; N CP,l is a downlink cyclic prefix length for OFDM symbol l in a slot; and T s is a basic time unit.
This invention relates to wireless communication systems, specifically to generating time-continuous signals for uplink transmissions in orthogonal frequency-division multiplexing (OFDM) systems. The problem addressed is the efficient and accurate generation of OFDM signals in the time domain, ensuring proper synchronization and subcarrier spacing while accommodating varying uplink bandwidth configurations and cyclic prefix lengths. The method involves generating a time-continuous signal defined by a mathematical expression that sums contributions from multiple subcarriers. The signal is constructed using a series of resource elements, each associated with a specific subcarrier and OFDM symbol. The expression incorporates parameters such as the resource block size (N sc RB), uplink bandwidth configuration (N RB UL), subcarrier spacing (Δf), cyclic prefix length (N CP,l), and a basic time unit (T s). The resource block size defines the number of subcarriers per block, while the uplink bandwidth configuration scales the total bandwidth. The cyclic prefix length varies per OFDM symbol to account for different propagation delays. The resulting signal ensures proper alignment and spacing of subcarriers, facilitating reliable uplink transmissions in wireless communication systems.
22. The method of claim 21 , wherein the time-continuous signal is generated in a single carrier frequency division multiple access (SC-FDMA) symbol.
This invention relates to wireless communication systems, specifically improving signal generation in Single Carrier Frequency Division Multiple Access (SC-FDMA) systems. SC-FDMA is used in uplink transmissions to reduce peak-to-average power ratio (PAPR) compared to OFDMA, but generating time-continuous signals for SC-FDMA symbols remains challenging. The invention addresses this by generating a time-continuous signal within a single SC-FDMA symbol, ensuring seamless transmission without discontinuities that could degrade performance. The method involves processing a discrete-time signal to produce a continuous-time waveform. This includes applying a windowing function to smooth transitions between symbols, preventing abrupt changes that cause spectral leakage or interference. The windowing function is designed to maintain orthogonality between subcarriers while minimizing out-of-band emissions. Additionally, the method may incorporate cyclic prefix insertion to further reduce inter-symbol interference (ISI) and improve signal integrity over multipath channels. The technique is particularly useful in mobile devices where power efficiency and signal quality are critical. By generating the time-continuous signal within a single SC-FDMA symbol, the system avoids the need for complex interpolation or additional processing steps, reducing computational overhead. The invention ensures compliance with spectral mask requirements while maintaining low PAPR, making it suitable for modern wireless standards like LTE and 5G.
23. The method of claim 1 , wherein the transform precoding generates a plurality of quasi-orthogonal complex-valued spreading codes to provide a superposition of the plurality of OFDM subcarriers with a reduced peak-to-average-power ratio.
This invention relates to wireless communication systems, specifically techniques for reducing peak-to-average power ratio (PAPR) in orthogonal frequency-division multiplexing (OFDM) transmissions. OFDM is widely used in modern wireless standards, but it suffers from high PAPR, which can lead to signal distortion and reduced power efficiency in transmitters. The invention discloses a method for generating quasi-orthogonal complex-valued spreading codes to precode OFDM subcarriers. These spreading codes are designed to superpose multiple OFDM subcarriers in a way that reduces PAPR while maintaining orthogonality between subcarriers. The precoding process involves applying the spreading codes to the OFDM subcarriers before transmission, ensuring that the resulting signal has a lower peak power relative to its average power. This technique helps mitigate the PAPR issue without significantly increasing computational complexity or degrading spectral efficiency. The quasi-orthogonal nature of the spreading codes allows for efficient multiplexing of multiple data streams while preserving orthogonality, which is critical for reliable signal recovery at the receiver. The method can be applied in various wireless communication systems, including 5G and beyond, where PAPR reduction is essential for improving transmitter power efficiency and reducing out-of-band emissions. The invention provides a practical solution to enhance the performance of OFDM-based systems by optimizing the precoding process to achieve lower PAPR.
24. An apparatus, comprising: a processor; and a non-transitory computer-readable memory communicatively coupled to the processor, the memory including a set of instructions stored thereon and executable by the processor for: dividing a block of complex-valued symbols into a plurality of sets of complex-valued symbols; transform precoding each of the plurality of sets of complex-valued symbols into a block of transform precoded complex-valued symbols; and generating an Orthogonal Frequency Division Multiplex (OFDM) signal comprising a plurality of OFDM subcarriers modulated with the transform-precoded complex-valued symbols, wherein the transform precoding generates a plurality of orthogonal spreading codes to provide a superposition of the plurality of OFDM subcarriers with a reduced peak-to-average-power ratio.
This invention relates to wireless communication systems, specifically to techniques for reducing the peak-to-average-power ratio (PAPR) in Orthogonal Frequency Division Multiplexing (OFDM) signals. OFDM is widely used in wireless communications but suffers from high PAPR, which can degrade power efficiency and signal quality. The invention addresses this by using transform precoding to spread data symbols across multiple subcarriers, reducing PAPR while maintaining orthogonality. The apparatus includes a processor and a non-transitory memory storing instructions for processing complex-valued symbols. The system divides a block of these symbols into multiple sets, then applies transform precoding to each set. This precoding generates orthogonal spreading codes, which distribute the symbols across OFDM subcarriers in a way that minimizes power fluctuations. The result is an OFDM signal with lower PAPR, improving transmitter efficiency and reducing distortion. The orthogonal spreading ensures that the subcarriers remain orthogonal, preserving the benefits of OFDM while mitigating its PAPR drawbacks. This approach is particularly useful in high-power transmission scenarios where PAPR reduction is critical.
25. The apparatus of claim 24 , wherein the transform precoding spreads the block of complex-valued symbols with a plurality of orthogonal spreading codes comprising complex-valued coefficients of a discrete Fourier transform (DFT) to produce the block of transform-precoded complex-valued symbols.
This invention relates to wireless communication systems, specifically to apparatuses for transform precoding in multi-carrier modulation schemes like OFDM. The problem addressed is improving signal transmission efficiency and reliability by applying orthogonal spreading codes to data symbols before modulation. The apparatus includes a transform precoder that processes a block of complex-valued symbols by spreading them with a set of orthogonal spreading codes. These spreading codes are derived from the complex-valued coefficients of a discrete Fourier transform (DFT), ensuring orthogonality across the spread symbols. The output is a block of transform-precoded complex-valued symbols, which are then further processed for transmission. This technique enhances spectral efficiency and reduces interference by leveraging the orthogonality properties of DFT-based spreading codes. The apparatus may also include components for generating the spreading codes, mapping the precoded symbols to subcarriers, and performing inverse fast Fourier transform (IFFT) operations to convert the frequency-domain symbols into time-domain signals for transmission. The use of DFT-based spreading codes allows for efficient implementation and compatibility with existing multi-carrier communication standards.
26. The apparatus of claim 25 , wherein the DFT is a fast Fourier transform (FFT).
Technical Summary: This invention relates to signal processing systems, specifically apparatuses that perform discrete Fourier transforms (DFTs) to analyze frequency components of signals. The problem addressed is improving computational efficiency in frequency-domain analysis, particularly in applications requiring real-time processing or low-power operation. The apparatus includes a signal input module that receives an input signal, a DFT processing module that converts the signal from the time domain to the frequency domain, and an output module that provides the transformed data. The DFT processing module is optimized to use a fast Fourier transform (FFT) algorithm, which reduces computational complexity compared to traditional DFT methods. The FFT implementation leverages symmetries and periodicity properties of the Fourier transform to minimize the number of arithmetic operations, making it suitable for high-speed or resource-constrained environments. The apparatus may further include preprocessing modules for signal conditioning, such as filtering or windowing, to enhance the quality of the frequency-domain output. Post-processing modules may also be included to extract specific frequency components or features for further analysis. The system is designed to be adaptable to various signal types, including audio, radar, or communication signals, where efficient frequency analysis is critical. By employing an FFT-based DFT, the apparatus achieves faster processing times and lower power consumption, making it ideal for embedded systems, portable devices, or real-time monitoring applications. The invention focuses on optimizing the core transformation step while maintaining flexibility in input and output handling.
29. The apparatus of claim 24 , comprising instructions for: mapping the block of transform-precoded complex-valued symbols to physical resource blocks assigned for transmission of a physical uplink shared channel.
This invention relates to wireless communication systems, specifically methods for efficiently transmitting data in uplink communications. The problem addressed is the need to optimize the mapping of transform-precoded complex-valued symbols to physical resource blocks (PRBs) in a physical uplink shared channel (PUSCH). Transform precoding is used to improve spectral efficiency and reduce peak-to-average power ratio (PAPR) in uplink transmissions, but mapping these precoded symbols to PRBs must be done in a way that maintains performance and compatibility with the communication protocol. The apparatus includes instructions for mapping a block of transform-precoded complex-valued symbols to PRBs assigned for PUSCH transmission. The transform precoding process involves applying a discrete Fourier transform (DFT) to the input data symbols, which spreads the energy of each symbol across multiple subcarriers. This precoding step is followed by a mapping step that assigns the precoded symbols to specific PRBs in the frequency domain. The mapping must account for the resource allocation scheme, ensuring that the precoded symbols are correctly placed within the assigned PRBs while maintaining orthogonality and minimizing interference. The apparatus may also include additional components for generating the transform-precoded symbols, such as a DFT module and a modulation module, as well as a controller for managing the resource allocation and transmission parameters. The overall system ensures efficient uplink data transmission with improved spectral efficiency and reduced PAPR, making it suitable for modern wireless communication standards like 5G and beyond.
30. The apparatus of claim 29 , wherein the mapping is responsive to an assignment of spectrum resources for selecting a plurality of OFDM subcarriers corresponding to at least one OFDM symbol interval.
This invention relates to wireless communication systems, specifically to apparatuses for managing spectrum resources in Orthogonal Frequency Division Multiplexing (OFDM) systems. The problem addressed is the efficient allocation and selection of OFDM subcarriers to optimize spectrum utilization and communication performance. The apparatus includes a mapping component that dynamically assigns spectrum resources by selecting multiple OFDM subcarriers corresponding to at least one OFDM symbol interval. This selection is responsive to the assignment of spectrum resources, ensuring that the chosen subcarriers align with the allocated spectrum. The apparatus may also include a resource allocation module that determines the available spectrum resources and a subcarrier selection module that identifies the specific subcarriers to be used based on the allocated resources. The system may further incorporate a modulation and coding scheme selector to optimize data transmission over the selected subcarriers. The invention aims to improve spectral efficiency, reduce interference, and enhance data throughput by dynamically mapping subcarriers to available spectrum resources. This approach is particularly useful in wireless communication systems where spectrum allocation is dynamic and must adapt to varying channel conditions and user demands. The apparatus ensures that the selected subcarriers are compatible with the allocated spectrum, minimizing wasted resources and improving overall system performance.
31. The apparatus of claim 29 , wherein at least one of the transform precoding and the mapping is configured to weight each of the plurality of OFDM subcarriers with an amplitude scaling factor to adjust gain of the superposition.
This invention relates to wireless communication systems, specifically to apparatuses for superposition coding in orthogonal frequency-division multiplexing (OFDM) systems. The problem addressed is optimizing signal transmission by adjusting the gain of superimposed signals across multiple OFDM subcarriers to improve spectral efficiency and reliability. The apparatus includes a superposition coding module that combines multiple data streams into a single composite signal for transmission. A transform precoding module processes the composite signal to prepare it for OFDM modulation. A mapping module assigns the processed signal to multiple OFDM subcarriers. The key innovation is that either the transform precoding or the mapping module (or both) applies an amplitude scaling factor to each subcarrier. This scaling adjusts the gain of the superposition, allowing dynamic control over signal power distribution across the frequency spectrum. By weighting subcarriers differently, the system can enhance performance in fading channels, reduce interference, or prioritize certain data streams. The apparatus may also include an OFDM modulator that converts the mapped subcarriers into a time-domain signal for transmission, and an antenna for broadcasting the signal. The amplitude scaling can be applied based on channel conditions, quality-of-service requirements, or other system parameters to optimize overall communication performance. This technique is particularly useful in multi-user or multi-layer transmission scenarios where efficient resource allocation is critical.
32. The apparatus of claim 29 , wherein the mapping is configured to select the plurality of OFDM subcarriers according to at least one of a frequency division multiple access scheme, a time division multiple access scheme, a space division multiple access scheme, a code division multiple access scheme, and a frequency-hoping scheme.
This invention relates to wireless communication systems, specifically apparatuses for selecting and mapping orthogonal frequency-division multiplexing (OFDM) subcarriers in multi-user environments. The problem addressed is efficient resource allocation to maximize spectral efficiency while minimizing interference among users in wireless networks. The apparatus includes a mapping module that dynamically assigns a plurality of OFDM subcarriers to multiple users based on predefined access schemes. The mapping can be configured to implement various multiple access techniques, including frequency division multiple access (FDMA), time division multiple access (TDMA), space division multiple access (SDMA), code division multiple access (CDMA), or frequency-hopping schemes. These techniques allow the system to allocate subcarriers in different domains—frequency, time, spatial, code, or frequency-hopping patterns—to optimize performance. The apparatus may also include a subcarrier selection module that identifies available subcarriers and a user allocation module that assigns subcarriers to users based on channel conditions, user priorities, or other criteria. The mapping module ensures that the selected subcarriers are distributed according to the chosen multiple access scheme, reducing collisions and improving overall throughput. This flexible approach allows the system to adapt to different network conditions and user demands, enhancing efficiency in wireless communications.
33. The apparatus of claim 24 , comprising instructions for: scrambling a block of bits of one subframe of a physical uplink shared channel resulting in a block of scrambled bits; and modulating the block of scrambled bits resulting in the block of complex-valued symbols.
This invention relates to wireless communication systems, specifically to methods for processing data in the physical uplink shared channel (PUSCH) of a wireless communication system. The problem addressed is efficient and secure transmission of uplink data by scrambling and modulating data blocks to ensure proper encoding and transmission. The apparatus includes a processor configured to execute instructions for scrambling a block of bits from one subframe of the PUSCH. The scrambling process transforms the original block of bits into a scrambled block of bits, enhancing security and reducing interference. Following scrambling, the scrambled block of bits is modulated to produce a block of complex-valued symbols. These symbols are suitable for transmission over the wireless channel, ensuring reliable data delivery. The scrambling step may involve applying a pseudo-random sequence or a predefined pattern to the original bit block, which helps in distinguishing different user transmissions and mitigating interference. The modulation step converts the scrambled bits into complex-valued symbols using techniques such as Quadrature Phase Shift Keying (QPSK) or higher-order modulation schemes, depending on the system requirements. This process ensures that the data is properly formatted for transmission while maintaining integrity and minimizing errors. The invention improves the reliability and security of uplink data transmission in wireless communication systems by combining scrambling and modulation techniques in a structured manner. This approach is particularly useful in systems where multiple users share the same uplink resources, such as in Long-Term Evolution (LTE) or 5G New Radio (NR) networks.
34. The apparatus of claim 33 , wherein the scrambling is configured to scramble the block of bits into a block of scrambled bits with at least one pseudo-noise code.
This invention relates to a communication system apparatus that improves signal security and interference mitigation by scrambling data blocks using pseudo-noise (PN) codes. The apparatus processes a block of bits by applying a scrambling operation to transform it into a block of scrambled bits. The scrambling is performed using at least one pseudo-noise code, which introduces controlled randomness to the data. This technique enhances security by making the transmitted signal harder to intercept and decode without knowledge of the PN code. Additionally, it reduces interference in multi-user or multi-device environments by ensuring that signals from different sources appear uncorrelated. The apparatus may include a scrambler module that receives the input bit block and applies the PN code-based scrambling, followed by a transmitter that sends the scrambled bits over a communication channel. The use of PN codes allows for synchronization and descrambling at the receiver, ensuring reliable data recovery. This method is particularly useful in wireless communication systems, satellite links, or any scenario where secure and interference-resistant data transmission is required. The invention builds on prior techniques by optimizing the scrambling process to balance security, complexity, and performance.
35. The apparatus of claim 24 , wherein the transform precoding is applied according to z ( l · M sc PUSCH + k ) = 1 M sc PUSCH ∑ i = 0 M sc PUSCH - 1 d ( l · M sc PUSCH + i ) e - j 2 π ik M sc PUSCH , wherein: the block of complex-valued symbols and the block of transform-precoded complex-valued symbol comprises a plurality of resource elements; l represents a time-domain index of each of the plurality of resource elements; k represents a frequency-domain index of each of the plurality of resource elements; M sc PUSCH is a scheduled bandwidth for uplink transmission expressed as a number of subcarriers; d(l·M sc PUSCH +i) represents resource elements of the block of complex-valued symbols; and z(l·M sc PUSCH +k) represents resource elements of the block of transform precoded complex-valued symbols.
This invention relates to wireless communication systems, specifically to a method for applying transform precoding to uplink transmissions in a physical uplink shared channel (PUSCH). The problem addressed is the efficient and accurate transformation of complex-valued symbols in uplink communications to improve transmission performance. The apparatus includes a processing unit configured to perform transform precoding on a block of complex-valued symbols. The precoding is applied using a discrete Fourier transform (DFT) operation, where each resource element in the time-frequency grid is processed according to the formula z(l·M sc PUSCH + k) = (1/M sc PUSCH) * Σ [d(l·M sc PUSCH + i) * e^(-j * 2π * i*k / M sc PUSCH)], where l is the time-domain index, k is the frequency-domain index, and M sc PUSCH is the scheduled bandwidth in subcarriers. The input symbols d(l·M sc PUSCH + i) are transformed into precoded symbols z(l·M sc PUSCH + k) across the allocated bandwidth. This method ensures proper mapping of symbols to resource elements while maintaining orthogonality and minimizing interference in uplink transmissions. The apparatus may further include components for generating the input symbols and transmitting the precoded symbols over the uplink channel. The invention improves spectral efficiency and reliability in wireless communications by optimizing the precoding process.
36. The apparatus of claim 35 , wherein: the transform precoding spreads the block of complex-valued symbols with a plurality of orthogonal spreading codes comprising complex-valued coefficients of a discrete Fourier transform (DFT) to produce the block of transform precoded complex-valued symbols; and M sc PUSCH is a length of the DFT corresponding to the plurality of orthogonal spreading codes.
This invention relates to wireless communication systems, specifically to apparatuses for transmitting data using transform precoding in uplink communications. The problem addressed is improving the efficiency and reliability of data transmission in scenarios where multiple users share the same time-frequency resources, such as in uplink multi-user multiple-input multiple-output (MU-MIMO) systems. The apparatus includes a transmitter configured to generate a block of complex-valued symbols for uplink transmission. A transform precoding module spreads these symbols using a set of orthogonal spreading codes derived from the complex-valued coefficients of a discrete Fourier transform (DFT). The DFT length, denoted as M sc PUSCH, determines the number of orthogonal spreading codes available. The precoded symbols are then transmitted over a physical uplink shared channel (PUSCH). The orthogonal spreading codes ensure that multiple users' transmissions can be distinguished at the receiver, reducing interference and improving spectral efficiency. The DFT-based spreading also helps maintain low peak-to-average power ratio (PAPR), which is beneficial for power-limited mobile devices. The apparatus may further include error correction encoding and modulation stages to enhance transmission reliability. The use of DFT-based precoding is particularly advantageous in scenarios requiring efficient resource utilization and interference mitigation in uplink communications.
37. The apparatus of claim 36 , wherein: each transform-precoded set of complex-valued symbols of the block of transform-precoded complex-valued symbols is a single-carrier frequency division multiple access symbol; and said each transform precoded set of complex-valued symbols is processed by the DFT.
This invention relates to wireless communication systems, specifically improving data transmission efficiency in single-carrier frequency division multiple access (SC-FDMA) systems. The problem addressed is optimizing the processing of complex-valued symbols to enhance spectral efficiency and reduce interference in multi-user environments. The apparatus includes a processing system that generates a block of transform-precoded complex-valued symbols. Each set of these symbols within the block is an SC-FDMA symbol, meaning it is designed for orthogonal transmission in a multi-user context. The processing system applies a discrete Fourier transform (DFT) to each set of symbols before transmission. This DFT precoding step converts the time-domain symbols into the frequency domain, enabling efficient allocation of subcarriers and minimizing inter-user interference. The apparatus further includes a transmitter that modulates the DFT-processed symbols onto a carrier signal for wireless transmission. The system may also include a receiver configured to demodulate received signals and apply an inverse DFT to recover the original complex-valued symbols. The use of DFT precoding in SC-FDMA systems improves power efficiency and spectral containment, making it suitable for uplink communications in cellular networks. The invention aims to enhance data throughput and reliability in wireless communication systems by optimizing symbol processing techniques.
38. The apparatus of claim 36 , wherein the time-continuous signal is generated in a single carrier frequency division multiple access (SC-FDMA) symbol.
This invention relates to wireless communication systems, specifically improving signal generation in Single Carrier Frequency Division Multiple Access (SC-FDMA) systems. SC-FDMA is used in uplink transmissions to reduce peak-to-average power ratio (PAPR) compared to OFDMA, but generating time-continuous signals efficiently remains challenging. The apparatus generates a time-continuous signal within a single SC-FDMA symbol. The signal is produced by processing input data through a discrete Fourier transform (DFT) to convert it into the frequency domain, followed by a subcarrier mapping step to allocate the transformed data to specific subcarriers. The mapped data is then converted back to the time domain using an inverse fast Fourier transform (IFFT). To ensure continuity, the time-domain signal is cyclically extended, typically by appending a cyclic prefix (CP) to the start of the symbol. This cyclic extension mitigates inter-symbol interference (ISI) and maintains signal integrity during transmission. The apparatus may also include a windowing function to smooth transitions between symbols, further reducing spectral leakage and improving signal quality. The generated signal is then transmitted over a wireless channel, where the time-continuous nature of the signal helps maintain low PAPR and efficient power amplification. This approach is particularly useful in mobile communication systems like LTE and 5G, where uplink efficiency and signal integrity are critical.
39. The method of claim 35 , wherein: the block of transform-precoded complex-valued symbols comprises carrier interferometry symbol values (w n ); and the block of complex-valued symbols comprises data symbols (s n ).
This invention relates to a method for processing complex-valued symbols in communication systems, particularly for improving signal transmission efficiency. The method addresses the challenge of efficiently encoding and transmitting data symbols while mitigating interference and distortion in wireless or wired communication channels. The technique involves transforming a block of data symbols (s_n) into a block of transform-precoded complex-valued symbols (w_n) using carrier interferometry techniques. This transformation helps in shaping the signal spectrum, reducing peak-to-average power ratio (PAPR), and enhancing robustness against channel impairments. The precoding process ensures that the symbols are optimized for transmission, improving spectral efficiency and reliability. The method is applicable in various communication standards, including 5G, Wi-Fi, and other high-speed data transmission systems, where efficient symbol encoding is critical for performance. By leveraging carrier interferometry, the approach provides a balance between computational complexity and transmission quality, making it suitable for real-time applications. The invention focuses on optimizing the symbol processing pipeline to enhance overall system performance while maintaining compatibility with existing communication protocols.
40. The method of claim 39 , wherein carrier interferometry code chip values are arranged with respect to a plurality of phase spaces.
Technical Summary: This invention relates to carrier interferometry (CI) systems, specifically addressing the arrangement of code chip values in phase space to improve signal processing and communication efficiency. Carrier interferometry is a modulation technique used in wireless communication systems to encode data by manipulating the phase of a carrier signal. A key challenge in CI systems is efficiently organizing code chip values to minimize interference and maximize data throughput. The invention describes a method for arranging carrier interferometry code chip values across multiple phase spaces. Each phase space represents a distinct set of phase relationships that can be used to encode different data symbols. By distributing the code chip values across these phase spaces, the system can reduce interference between adjacent symbols and improve signal integrity. This arrangement allows for more efficient use of the available bandwidth, enabling higher data rates and better performance in noisy environments. The method involves mapping the code chip values to specific phase spaces based on predefined criteria, such as minimizing phase overlap or optimizing signal-to-noise ratio. The phase spaces may be defined by different modulation schemes, such as phase-shift keying (PSK) or quadrature amplitude modulation (QAM), depending on the system requirements. By carefully structuring the code chip values in this manner, the system can achieve more reliable data transmission and reception. This technique is particularly useful in high-density communication systems where multiple signals must coexist without significant interference. The arrangement of code chip values in phase space helps mitigate cross-talk and improves overall system robustness. The invention provi
41. The method of claim 40 , wherein the plurality of phase spaces comprises orthogonal phase spaces.
This invention relates to signal processing techniques for analyzing and manipulating signals in multiple phase spaces. The problem addressed is the need for more efficient and accurate signal representation and processing by leveraging orthogonal phase spaces, which can reduce redundancy and improve computational efficiency. The method involves processing a signal by transforming it into a plurality of phase spaces. These phase spaces are orthogonal to each other, meaning they are mathematically independent and do not overlap in their representation of the signal. By using orthogonal phase spaces, the method ensures that the signal components are uniquely represented in each space, avoiding redundant information and enhancing the clarity of the signal analysis. The transformation into orthogonal phase spaces can be applied to various types of signals, including but not limited to time-domain, frequency-domain, and time-frequency representations. The method may involve techniques such as Fourier transforms, wavelet transforms, or other mathematical operations that decompose the signal into orthogonal components. Once the signal is represented in the orthogonal phase spaces, further processing steps can be performed, such as filtering, feature extraction, or pattern recognition. The orthogonal nature of the phase spaces allows for more precise isolation of signal features, leading to improved accuracy in tasks like noise reduction, signal classification, or data compression. The use of orthogonal phase spaces is particularly beneficial in applications where signal integrity and computational efficiency are critical, such as in telecommunications, medical imaging, or audio processing. By minimizing redundancy and maximizing the distinctiveness of signal components, th
42. The method of claim 39 , wherein the number of carrier interferometry symbol values is different than the number of data symbols.
This invention relates to wireless communication systems, specifically methods for transmitting data using carrier interferometry modulation. The technology addresses the challenge of efficiently transmitting data symbols while managing spectral efficiency and interference in communication channels. The method involves generating carrier interferometry symbol values from data symbols, where the number of carrier interferometry symbol values differs from the number of data symbols. This allows for flexible modulation schemes that can adapt to varying channel conditions or system requirements. The carrier interferometry symbols are then transmitted over a communication channel, enabling reliable data transmission with reduced interference compared to traditional modulation techniques. The method may include preprocessing the data symbols before generating the carrier interferometry symbols, such as applying error correction coding or interleaving to improve transmission robustness. The carrier interferometry symbols are generated using a transformation process that spreads the data symbols across multiple frequency subcarriers, enhancing spectral efficiency. The transmitted symbols are received and processed by a receiver, which reconstructs the original data symbols by applying an inverse transformation. This approach improves communication performance by optimizing the relationship between data symbols and carrier interferometry symbols, allowing for better adaptation to dynamic channel conditions and higher data throughput. The method is particularly useful in wireless systems where spectral efficiency and interference management are critical.
43. The method of claim 40 , wherein each of the data symbol values is impressed upon one of the plurality of phase spaces.
This invention relates to a method for encoding data symbols in a communication system, particularly in a multi-dimensional modulation scheme. The problem addressed is the efficient and reliable transmission of data symbols by leveraging multiple phase spaces to improve spectral efficiency and robustness against noise and interference. The method involves assigning each data symbol a unique value, which is then mapped to a specific phase space within a multi-dimensional modulation framework. Each phase space represents a distinct region in the modulation space, allowing for parallel transmission of multiple data symbols. By distributing the data symbols across different phase spaces, the system enhances data throughput and reduces the likelihood of symbol collisions or errors during transmission. The technique may be applied in wireless communication systems, optical networks, or other high-speed data transmission environments where spectral efficiency and error resilience are critical. The use of multiple phase spaces enables higher-order modulation schemes, such as quadrature amplitude modulation (QAM) or orthogonal frequency-division multiplexing (OFDM), to be implemented more effectively. This approach also supports adaptive modulation, where the number of phase spaces can be dynamically adjusted based on channel conditions to optimize performance. The method ensures that each data symbol is uniquely associated with a phase space, preventing overlap and minimizing interference. This structured allocation improves signal integrity and facilitates accurate demodulation at the receiver. The invention is particularly useful in scenarios requiring high data rates and reliable communication in noisy or congested channels.
44. The method of claim 24 , wherein each of the plurality of sets of complex-valued symbols is a single carrier frequency division multiple access (SC-FDMA) symbol.
This invention relates to wireless communication systems, specifically improving the transmission of data symbols in uplink communications. The problem addressed is the efficient and reliable transmission of data in systems using Single Carrier Frequency Division Multiple Access (SC-FDMA), a modulation scheme commonly used in uplink transmissions to reduce peak-to-average power ratio (PAPR) and improve power efficiency. The method involves transmitting a plurality of sets of complex-valued symbols, where each set corresponds to a single SC-FDMA symbol. These symbols are generated by applying a discrete Fourier transform (DFT) to a sequence of data symbols, spreading them across multiple subcarriers while maintaining a single-carrier structure. The DFT-spread symbols are then mapped to subcarriers and converted back to the time domain using an inverse fast Fourier transform (IFFT). This process ensures low PAPR, which is critical for power-limited mobile devices. The method further includes techniques for handling multiple sets of symbols, such as time-domain multiplexing or frequency-domain multiplexing, to support multiple users or data streams. Error correction coding and modulation schemes (e.g., QPSK, 16-QAM) may be applied before DFT spreading to enhance reliability. The transmitted SC-FDMA symbols are received and processed by a receiver, which performs inverse operations (e.g., FFT, IDFT) to recover the original data. This approach optimizes uplink transmissions by balancing spectral efficiency, power efficiency, and complexity, making it suitable for modern wireless standards like LTE and 5G.
45. The method of claim 24 , comprising generating a time-continuous signal defined by: s l ( t ) = ∑ k = - [ N RB UL N sc RB / 2 ] [ N RB UL N sc RB / 2 ] - 1 a k ( - ) , l e j 2 π ( k + 1 / 2 ) Δ f ( t - N CP , l T s ) , wherein: N sc RB is a resource block size in a frequency domain express as a number of subcarriers; N RB UL is an uplink bandwidth configuration express in multiples of N sc RB ; a k (−) ,l is a value of a resource element; Δf is subcarrier spacing; N CP,l is a downlink cyclic prefix length for OFDM symbol 1 in a slot; and T s is a basic time unit.
This invention relates to wireless communication systems, specifically to generating time-continuous signals for uplink transmissions in orthogonal frequency-division multiplexing (OFDM) systems. The problem addressed is the efficient and accurate generation of OFDM signals in the time domain, particularly for uplink communications where precise signal construction is critical for maintaining synchronization and minimizing interference. The method involves generating a time-continuous signal defined by a mathematical expression that sums contributions from multiple subcarriers. The signal is constructed using a discrete set of resource elements, each associated with a complex value. The expression incorporates parameters such as the resource block size in the frequency domain, expressed as the number of subcarriers (N sc RB), the uplink bandwidth configuration (N RB UL), and the subcarrier spacing (Δf). The signal also accounts for the cyclic prefix length (N CP,l) and a basic time unit (T s) to ensure proper timing alignment. The summation spans a range of subcarriers determined by the uplink bandwidth and resource block size, with each term modulated by an exponential function that accounts for frequency and time offsets. This approach ensures accurate signal generation while maintaining compatibility with OFDM standards.
46. The apparatus of claim 24 , wherein the transform precoding generates a plurality of quasi-orthogonal complex-valued spreading codes to provide a superposition of the plurality of OFDM subcarriers with a reduced peak-to-average-power ratio.
This invention relates to wireless communication systems, specifically to apparatuses that use transform precoding to reduce peak-to-average-power ratio (PAPR) in orthogonal frequency-division multiplexing (OFDM) transmissions. The problem addressed is the high PAPR in OFDM signals, which can lead to inefficiencies in power amplifiers and increased distortion. The apparatus includes a transform precoder that generates a plurality of quasi-orthogonal complex-valued spreading codes. These codes are applied to a set of OFDM subcarriers, creating a superposition of the subcarriers. The quasi-orthogonal nature of the spreading codes ensures that the combined signal maintains low PAPR while preserving orthogonality between subcarriers. This reduces the likelihood of signal distortion and improves power amplifier efficiency. The transform precoder may use techniques such as discrete Fourier transform (DFT) or other linear transformations to generate the spreading codes. The apparatus may also include a mapping module to assign data symbols to the subcarriers before precoding. The resulting precoded signal is then transmitted over a wireless channel, where the reduced PAPR allows for more efficient power usage and better signal integrity. This approach is particularly useful in high-data-rate applications where minimizing PAPR is critical for maintaining signal quality.
47. A computer program product, comprising a non-transitory computer readable hardware storage device having computer readable program code stored therein, said program code containing instructions executable by one or more processors of a computer system to implement a method comprising: dividing a block of complex-valued symbols into a plurality of sets of complex-valued symbols; and transform precoding each of the plurality of sets of complex-valued symbols into a block of transform precoded complex-valued symbols; and generating an Orthogonal Frequency Division Multiplex (OFDM) signal comprising a plurality of OFDM subcarriers modulated with the transform-precoded complex-valued symbols, wherein the transform precoding generates a plurality of orthogonal spreading codes to provide a superposition of the plurality of OFDM subcarriers with a reduced peak-to-average-power ratio.
This invention relates to wireless communication systems, specifically to techniques for reducing the peak-to-average-power ratio (PAPR) in Orthogonal Frequency Division Multiplexing (OFDM) signals. OFDM is widely used in wireless communications but suffers from high PAPR, which can degrade power efficiency and signal quality. The invention addresses this by applying transform precoding to complex-valued symbols before OFDM modulation. The method involves dividing a block of complex-valued symbols into multiple sets. Each set undergoes transform precoding, which generates orthogonal spreading codes. These codes are then used to modulate OFDM subcarriers, creating a superposition of subcarriers with reduced PAPR. The transform precoding step ensures that the resulting OFDM signal maintains orthogonality while minimizing power fluctuations, improving transmission efficiency and reliability. The approach is implemented via a computer program product stored on a non-transitory hardware storage device, containing executable instructions for a computer system to perform the method. This technique is particularly useful in high-data-rate wireless systems where PAPR reduction is critical for maintaining performance.
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August 20, 2019
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